About 20% of the kids in Mississippi are obese, a new government study has found. On the contrary, Oregon kids are at the bottom of the obesity tally. Also, their leanness is a mystery for the health officials, who would be more than happy in solving it to meet federal goals for childhood obesity. The study also found big gaps between regions and ballooning obesity rates in many states from 2003 to 2007.

According to the study, in 2007 over 16% of American children in the age group of 10-17 years were not just overweight, but obese - a 10% rise from 2003. With the lowest rate of obesity - defined as body mass index in the 95th percentile or above - at just under 10%, Oregon was the star in the study. Also, it was the only state whose childhood obesity count witnessed a significant dip between 2003 and 2007.

Appearing in May's Archives of Pediatrics and Adolescent Medicine, even the best states fell short in the childhood obesity goal of 5% set under a federal Healthy People 2010 initiative. Only Wyoming girls inched near to the goal.

"You've got such wide differences at the geographic level, which means there is potential to further reduce obesity," said lead author Gopal Singh, an Epidemiologist with the U. S. Health Resources and Services Administration.